By David Newhardt Photos by The Author

Also from Issue 72

UPGRADING A CORVETTE’S PERFORMANCE often puts an owner on a slippery slope. More power usually leads to even more power, and street cars slide into race-car territory. It happened to David Busch, owner of Loud Pedal Motorsports, Inc, in Tempe, Arizona. He decided he wanted to increase the horsepower of his sixth-gen Z06. One thing led to another, and before he knew it, he had more than doubled the car’s power output. Dubbed Z0666, the Corvette is like the Four Horseman on four wheels.

Busch got into Corvettes like many have, with a friend lending him the keys to one—in this case, a red C3 convertible. In 2000, Busch bought a Corvette of his own: a new C5 convertible. At that point, he knew that Chevrolet’s sports car was going to be a major part of his life. Business needs saw the 2000 go to a new home, but by 2004, another Corvette was in the garage—a 2003 50th Anniversary convertible. The Corvette’s performance impressed Busch, but he felt that with a handful of standard hop-up tricks, it could deliver more of everything. In went a more aggressive camshaft, an aftermarket exhaust was bolted on and the standard tires were swapped out for a sticker set of rubber. Busch was stunned with the results, but the changes only whet his appetite for increased performance.

In 2005, when he heard that Chevrolet was going to be releasing the C6 Z06, he immediately placed his order. Busch and his wife flew to Kentucky to pick up their 505-horsepower machine at the factory, and the twisty roads around Bowling Green were the perfect venue to break it in. Busch swore that he’d keep this Corvette bone stock, as surely 505 horsepower was enough for anybody. Sense where this is going?

After about two years, Busch was itching for a little more power. The same engine and exhaust modifications he’d installed on the C5 were applied to the Z06, and he ended up with 535 horsepower at the rear tires. The exhaust note was burly and commanding, and the engine idled with the lazy lope of an old big block. After founding Loud Pedal Motorsports in 2008, Busch decided to ramp up the Z06’s performance even more as a demonstration of LPM’s engineering prowess. It ended up being a very steep ramp.

The stock LS7 V8 didn’t have the room for power growth that Busch was envisioning, so it was yanked out, and an LSX454 crate engine from GM Performance Parts was installed. As delivered, this mill cranks out 620 ponies—no insignificant increase over a stock LS7. But Busch had “more” on his mind, and the path to “more” is often paved with forced induction. Busch knew that the LSX454 block and LS7 6-bolt heads could handle considerable boost levels, so he approached Procharger about designing a supercharger package that could churn up a lot of boost while still fitting under the OEM hood. The result was the F1D blower, delivering a maximum of 14.5 pounds of boost.

But just bolting on a supercharger and expecting a livable powerplant is an unrealistic proposition. Busch paid attention to the entire package, from engine components to driveline survivability. A Nick Williams 102mm throttle body sits atop a FASTLSXR intake manifold, and 95-pound High Impedance injectors fill the combustion chambers with pump gas.

Other projects in Loud Pedal Motorsports past had used superchargers to help generate serious power, but belt slippage, even with the use of an 8-rib belt, had been an issue. Busch solved this problem on his Z0666 by using an HPE Flip Drive dedicated belt system. Even though the Corvette’s engine reaches its horsepower peak at a lofty 6,200 rpm, the HPE belt is as happy as a clam. In addition, a Ron Davis radiator was fitted, and during the protracted photo shoot, on a hot Arizona day, the temp needle was locked in the lower portion of the gauge.